Exploring a peer-led strategy to link recent Latino immigrants to HIV testing This R21 application proposes 2 years of exploratory research that will inform the design of a peer chain referral strategy to engage recent Latino immigrant men (RLIM) in voluntary counseling and testing (VCT). RLIM tend to arrive in the US healthy and at prime working age from low prevalence areas. However, in the US, RLIM rapidly adopt risky practices and become disproportionally affected by HIV. The vulnerability to HIV among RLIM has been attributed to structural and motivational factors, including uncertain immigration status, lack of resources, disconnection from services, high levels of stigma, and unawareness of HIV risk, factors that also hamper RLIM's access to venue- based and outreach HIV prevention efforts. Whereas RLIM are not reached by traditional HIV prevention approaches, they form associations with other RLIM to obtain information and referrals and cope with barriers associated with language, skills, and legal status in the US. Social networks approaches use these associations to penetrate hidden groups and link them to services and research. This project will explore the feasibility of peer chain referral to link RLIM to VCT, an essential tool to prevent HIV, and the cornerstone of test and treat strategies. We also endeavor to identify factors that can increase the ability of this method to reach at risk RLIM who would not otherwise have accessed VCT. We will recruit 250 RLIM for VCT with a peer chain referral strategy. We will compare them with 125 RLIM tested in customary VCT programs. We will identify the degree to which peer-referred RLIM are at risk for HIV, have few connections with services, perceive high levels of stigma and low risk for HIV, and have riskier and less supportive social networks. We will interview RLIM after they referred their peers to explore the relationships, settings and communications that are most promising to refer the most disadvantaged RLIM to VCT. Findings will serve to inform an enhanced peer chain referral strategy to engage RLIM in VCT.